Introduction: Optic neuritis is a condition associated with various systemic diseases, such as multiple sclerosis, and is also considered a rare complication of Lyme disease., Case: A 46-year-old white woman presented with sudden onset of bilateral vision loss. After extensive workup, she was diagnosed with Lyme optic neuritis based on the clinical presentation and positive serology. She was treated with doxycycline for 2 weeks., Discussion: Lyme disease is caused by infection with the spirochete Borrelia burgdorferi. The most commonly affected areas include the skin, joints, heart, and nervous system. Lyme optic neuritis is a challenging diagnosis and therefore often underreported. Doxycycline or ceftriaxone for 2 weeks are recommended for treatment., Conclusion: We report this case to increase awareness among clinicians to include Lyme disease in the differential diagnosis of optic neuritis for unexplained cases of vision loss, particularly in Lyme endemic areas., (Copyright© Wisconsin Medical Society.)